Group B Streptococcus Colonization Detection, NAA With Reflex to Susceptibilities
Use
Antepartum detection of group B β-hemolytic streptococci in patients who are at high risk for anaphylactic shock due to penicillin allergy.
Special Instructions
It is strongly recommended to collect both vaginal and rectal swab specimens to maximize sensitivity of GBS detection. Cervical, perianal, perirectal, or perineal specimens are not acceptable, and a speculum should not be used for culture collection. The test requires a selective broth enrichment culture followed by real-time PCR. In case of penicillin-allergic women, reflex susceptibility testing is advised.
Limitations
A positive result does not necessarily indicate the presence of viable organisms. Patients who have used systemic or topical (vaginal) antibiotic treatment in the week prior or those diagnosed with placenta previa should not be tested using this assay. Susceptibility testing is generally not performed as GBS is universally susceptible to penicillin, though exceptions are made for penicillin-allergic patients at high risk for anaphylactic shock.
Methodology
PCR-based (qPCR)
Biomarkers
LOINC Codes
- 48683-7
- 48683-7
Result Turnaround Time
2-5 days
Related Documents
For more information, please review the documents below
Specimen
Cervical Swab
Volume
Single or double bacterial swab in Amies agar gel transport, ESwab® or equivalent
Minimum Volume
Single bacterial swab in Amies agar gel transport, ESwab® or equivalent
Container
Bacterial Cult Trans Swab with Media or ESwab®
Collection Instructions
Swab the lower vagina (vaginal introitus), followed by the rectum using the same swab. Move swab from side to side, or rotate the swab at the collection site, allowing several seconds for absorption of organisms by the swab. Avoid using a speculum.
Storage Instructions
Specimen is stable for 24 hours at room temperature. If arrival at lab will extend beyond 24 hours, refrigerate.
Causes for Rejection
Inappropriate specimen transport; inappropriate transport conditions; improper labeling; specimen received after prolonged delay (more than 48 hours); cervical/endocervical, perianal, perirectal or perineal specimen or any source other than vagina and rectum
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 24 hours |